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root/radiance/ray/src/common/bsdf.h
Revision: 2.5
Committed: Fri Feb 18 02:41:55 2011 UTC (13 years, 2 months ago) by greg
Content type: text/plain
Branch: MAIN
Changes since 2.4: +7 -1 lines
Log Message:
Minor fixes and adjustments

File Contents

# User Rev Content
1 greg 2.5 /* RCSid $Id: bsdf.h,v 2.4 2011/02/18 00:40:25 greg Exp $ */
2 greg 2.4 /*
3     * bsdf.h
4     *
5     * Declarations for bidirectional scattering distribution functions.
6     * Assumes <stdio.h> already included.
7     *
8     * A material is oriented in right-hand coordinate system with X-axis
9     * in the surface plane pointed to the right as seen from the front.
10     * This means the Y-axis is "up" and the Z-axis is the surface normal.
11     *
12     * BSDF vectors always oriented away from surface, even when "incident."
13     *
14     * Created by Greg Ward on 1/10/11.
15     *
16     */
17    
18     #ifndef _BSDF_H_
19     #define _BSDF_H_
20    
21     #include "fvect.h"
22     #include "ccolor.h"
23    
24     #ifdef __cplusplus
25     extern "C" {
26     #endif
27    
28     #define SDnameLn 128 /* maximum BSDF name length */
29     #define SDmaxCh 3 /* maximum # spectral channels */
30    
31     /* Component flags for SDsampBSDF() and SDhemiScatter() */
32     #define SDsampR 0x1 /* include reflection */
33     #define SDsampT 0x2 /* include transmission */
34     #define SDsampS 0x3 /* include scattering (R+T) */
35     #define SDsampSp 0x4 /* include non-diffuse portion */
36     #define SDsampDf 0x8 /* include diffuse portion */
37     #define SDsampSpR 0x5 /* include non-diffuse reflection */
38     #define SDsampSpT 0x6 /* include non-diffuse transmission */
39     #define SDsampSpS 0x7 /* include non-diffuse scattering */
40     #define SDsampAll 0xF /* include everything */
41    
42     /* Projected solid angle query flags fos SDsizeBSDF() */
43     #define SDqueryInc 0x1 /* query incoming vector */
44     #define SDqueryOut 0x2 /* query outgoing vector */
45     #define SDqueryMin 0x4 /* query minimum proj. solid angle */
46     #define SDqueryMax 0x8 /* query maximum proj. solid angle */
47    
48     /* Error codes: normal return, out of memory, file i/o, file format, bad argument,
49     bad data, unsupported feature, internal error, unknown error */
50     typedef enum {SDEnone=0, SDEmemory, SDEfile, SDEformat, SDEargument,
51     SDEdata, SDEsupport, SDEinternal, SDEunknown} SDError;
52    
53     /* English ASCII strings corresponding to ennumerated errors */
54     extern const char *SDerrorEnglish[];
55    
56     /* Additional information on last error (ASCII English) */
57     extern char SDerrorDetail[];
58    
59     /* Holder for BSDF value and spectral color */
60     typedef struct {
61     double cieY; /* photopic BSDF (Y) value */
62     C_COLOR spec; /* spectral and (x,y) color */
63     } SDValue;
64    
65     /* Cached, encoded, cumulative distribution for one incident (solid) angle */
66     #define SD_CDIST_BASE double cTotal; \
67     struct SDCDst_s *next
68     typedef struct SDCDst_s {
69     SD_CDIST_BASE; /* base fields first */
70     /* ...encoded distribution extends struct */
71     } SDCDst;
72    
73     /* Forward declaration of BSDF component */
74     typedef struct SDComp_s SDComponent;
75    
76     /* Methods needed to handle BSDF components (nothing is optional) */
77     typedef const struct {
78     /* return non-diffuse BSDF */
79     int (*getBSDFs)(float coef[SDmaxCh], const FVECT outVec,
80     const FVECT inVec, const void *dist);
81     /* query non-diffuse PSA for vector */
82     SDError (*queryProjSA)(double *psa, const FVECT vec,
83     int qflags, const void *dist);
84     /* get cumulative distribution */
85     const SDCDst *(*getCDist)(const FVECT inVec, SDComponent *sdc);
86     /* sample cumulative distribution */
87     SDError (*sampCDist)(FVECT outVec, double randX,
88     const SDCDst *cdp);
89     /* free a spectral BSDF component */
90     void (*freeSC)(void *dist);
91     } SDFunc;
92    
93     /* Structure to hold a spectral BSDF component (typedef SDComponent above) */
94     struct SDComp_s {
95     C_COLOR cspec[SDmaxCh]; /* component spectral bases */
96     SDFunc *func; /* methods for this component */
97     void *dist; /* loaded distribution data */
98     SDCDst *cdList; /* cumulative distribution cache */
99     };
100    
101     /* Container for non-diffuse BSDF components */
102     typedef struct {
103     double minProjSA; /* minimum projected solid angle */
104     double maxHemi; /* maximum directional hemispherical */
105     int ncomp; /* number of separate components */
106     SDComponent comp[1]; /* BSDF components (extends struct) */
107     } SDSpectralDF;
108    
109     /* Loaded BSDF data */
110     typedef struct {
111     char name[SDnameLn]; /* BSDF name (derived from file) */
112     char *mgf; /* geometric description (if any) */
113     float dim[3]; /* width, height, thickness (meters) */
114     SDValue rLambFront; /* diffuse front reflectance */
115     SDValue rLambBack; /* diffuse rear reflectance */
116     SDValue tLamb; /* diffuse transmission */
117     SDSpectralDF *rf, *rb, *tf; /* non-diffuse BSDF components */
118     } SDData;
119    
120     /* List of loaded BSDFs */
121     extern struct SDCache_s {
122     SDData bsdf; /* BSDF data */
123     unsigned refcnt; /* how many callers are using us? */
124     struct SDCache_s /* next in cache list */
125     *next;
126     } *SDcacheList; /* Global BSDF cache */
127    
128     /* BSDF cache retention preference */
129     #define SDretainNone 0 /* free unreferenced data (default) */
130     #define SDretainBSDFs 1 /* keep loaded BSDFs in cache */
131     #define SDretainAll 2 /* also keep cumulative cache data */
132    
133     extern int SDretainSet; /* set to SDretainNone by default */
134    
135     /*****************************************************************
136     * The following routines are less commonly used by applications.
137     */
138    
139     #define SDisLoaded(sd) ((sd)->rLambFront.spec.clock != 0)
140    
141     /* Report an error to the indicated stream (in English) */
142     extern SDError SDreportEnglish(SDError ec, FILE *fp);
143    
144     /* Shorten file path to useable BSDF name, removing suffix */
145     extern void SDclipName(char res[SDnameLn], const char *fname);
146    
147     /* Allocate new spectral distribution function */
148     extern SDSpectralDF *SDnewSpectralDF(int nc);
149    
150     /* Free a spectral distribution function */
151     extern void SDfreeSpectralDF(SDSpectralDF *df);
152    
153     /* Initialize an unused BSDF struct (clears to zeroes) */
154     extern void SDclearBSDF(SDData *sd);
155    
156     /* Load a BSDF struct from the given file (keeps name unchanged) */
157     extern SDError SDloadFile(SDData *sd, const char *fname);
158    
159     /* Free data associated with BSDF struct */
160     extern void SDfreeBSDF(SDData *sd);
161    
162     /* Find writeable BSDF by name, or allocate new cache entry if absent */
163     extern SDData *SDgetCache(const char *bname);
164    
165     /* Free cached cumulative distributions for BSDF component */
166     extern void SDfreeCumulativeCache(SDSpectralDF *df);
167    
168     /* Sample an individual BSDF component */
169     extern SDError SDsampComponent(SDValue *sv, FVECT outVec,
170     const FVECT inVec, double randX,
171     SDComponent *sdc);
172    
173     /* Convert 1-dimensional random variable to N-dimensional */
174     extern void SDmultiSamp(double t[], int n, double randX);
175    
176     /* Map a [0,1]^2 square to a unit radius disk */
177     void SDsquare2disk(double ds[2], double seedx, double seedy);
178    
179     /* Map point on unit disk to a unit square in [0,1]^2 range */
180     void SDdisk2square(double sq[2], double diskx, double disky);
181    
182     /*****************************************************************
183     * The calls below are the ones most applications require.
184     * All directions are assumed to be unit vectors.
185     */
186    
187     /* Get BSDF from cache (or load and cache it on first call) */
188     /* Report any problems to stderr and return NULL on failure */
189     extern const SDData *SDcacheFile(const char *fname);
190    
191     /* Free a BSDF from our cache (clear all if NULL) */
192     extern void SDfreeCache(const SDData *sd);
193    
194     /* Query projected solid angle resolution for non-diffuse BSDF direction */
195     extern SDError SDsizeBSDF(double *projSA, const FVECT vec,
196     int qflags, const SDData *sd);
197    
198     /* Return BSDF for the given incident and scattered ray vectors */
199     extern SDError SDevalBSDF(SDValue *sv, const FVECT outVec,
200     const FVECT inVec, const SDData *sd);
201    
202     /* Compute directional hemispherical scattering at given incident angle */
203     extern double SDdirectHemi(const FVECT inVec,
204     int sflags, const SDData *sd);
205    
206     /* Sample BSDF direction based on the given random variable */
207     extern SDError SDsampBSDF(SDValue *sv, FVECT outVec,
208     const FVECT inVec, double randX,
209     int sflags, const SDData *sd);
210    
211     /*****************************************************************
212     * Vector math for getting between world and local BSDF coordinates.
213     * Directions may be passed unnormalized to these routines.
214     */
215    
216     /* Compute World->BSDF transform from surface normal and up (Y) vector */
217     extern SDError SDcompXform(RREAL vMtx[3][3], const FVECT sNrm,
218     const FVECT uVec);
219    
220     /* Compute inverse transform */
221     extern SDError SDinvXform(RREAL iMtx[3][3], RREAL vMtx[3][3]);
222    
223     /* Transform and normalize direction (column) vector */
224     extern SDError SDmapDir(FVECT resVec, RREAL vMtx[3][3],
225     const FVECT inpVec);
226    
227 greg 2.5 /* System-specific BSDF loading routine (not part of our library) */
228     extern SDData *loadBSDF(char *name);
229    
230     /* System-specific BSDF error translator (not part of our library) */
231     extern char *transSDError(SDError ec);
232    
233 greg 2.4 /*################################################################*/
234     /*######### DEPRECATED DEFINITIONS AWAITING PERMANENT REMOVAL #######*/
235 greg 2.1 /*
236     * Header for BSDF i/o and access routines
237     */
238 greg 2.2
239 greg 2.4 #include "mat4.h"
240 greg 2.1 /* up directions */
241     typedef enum {
242     UDzneg=-3,
243     UDyneg=-2,
244     UDxneg=-1,
245     UDunknown=0,
246     UDxpos=1,
247     UDypos=2,
248     UDzpos=3
249     } UpDir;
250     /* BSDF coordinate calculation routines */
251     /* vectors always point away from surface */
252 greg 2.4
253     typedef int b_vecf2(FVECT v, int n, void *cd);
254     typedef int b_ndxf2(FVECT v, void *cd);
255     typedef double b_radf2(int n, void *cd);
256 greg 2.1
257     /* Bidirectional Scattering Distribution Function */
258     struct BSDF_data {
259     int ninc; /* number of incoming directions */
260     int nout; /* number of outgoing directions */
261 greg 2.3 float dim[3]; /* width, height, thickness (meters) */
262     char *mgf; /* geometric description (if any) */
263 greg 2.1 void *ib_priv; /* input basis private data */
264 greg 2.4 b_vecf2 *ib_vec; /* get input vector from index */
265     b_ndxf2 *ib_ndx; /* get input index from vector */
266     b_radf2 *ib_ohm; /* get input radius for index */
267 greg 2.1 void *ob_priv; /* output basis private data */
268 greg 2.4 b_vecf2 *ob_vec; /* get output vector from index */
269     b_ndxf2 *ob_ndx; /* get output index from vector */
270     b_radf2 *ob_ohm; /* get output radius for index */
271 greg 2.1 float *bsdf; /* scattering distribution data */
272     }; /* bidirectional scattering distrib. func. */
273    
274     #define getBSDF_incvec(v,b,i) (*(b)->ib_vec)(v,i,(b)->ib_priv)
275     #define getBSDF_incndx(b,v) (*(b)->ib_ndx)(v,(b)->ib_priv)
276     #define getBSDF_incohm(b,i) (*(b)->ib_ohm)(i,(b)->ib_priv)
277     #define getBSDF_outvec(v,b,o) (*(b)->ob_vec)(v,o,(b)->ob_priv)
278     #define getBSDF_outndx(b,v) (*(b)->ob_ndx)(v,(b)->ob_priv)
279     #define getBSDF_outohm(b,o) (*(b)->ob_ohm)(o,(b)->ob_priv)
280     #define BSDF_value(b,i,o) (b)->bsdf[(o)*(b)->ninc + (i)]
281    
282     extern struct BSDF_data *load_BSDF(char *fname);
283     extern void free_BSDF(struct BSDF_data *b);
284     extern int r_BSDF_incvec(FVECT v, struct BSDF_data *b, int i,
285     double rv, MAT4 xm);
286     extern int r_BSDF_outvec(FVECT v, struct BSDF_data *b, int o,
287     double rv, MAT4 xm);
288 greg 2.3 extern int getBSDF_xfm(MAT4 xm, FVECT nrm, UpDir ud, char *xfbuf);
289 greg 2.2
290 greg 2.4 /*######### END DEPRECATED DEFINITIONS #######*/
291     /*################################################################*/
292    
293     #ifdef __cplusplus
294     }
295     #endif
296     #endif /* ! _BSDF_H_ */